As of the census of 2000, there were 20,971 people, 8,302 households, and 5,562 families residing in the city. The population density was 2,337.3 people per square mile (902.7/km²). There were 8,818 housing units at an average density of 982.8/sq mi (379.6/km²). The racial makeup of the city was 87.19% White, 1.45% African American, 0.35% Native American, 0.48% Asian, 0.04% Pacific Islander, 3.49% from other races, and 1.00% from two or more races. Hispanic or Latino of any race were 12.65% of the population.
There were 8,302 households out of which 34.7% had children under the age of 18 living with them, 54.7% were married couples living together, 8.9% had a female householder with no husband present, and 33.0% were non-families. 28.5% of all households were made up of individuals and 12.3% had someone living alone who was 65 years of age or older. The average household size was 2.50 and the average family size was 3.09.
In the city the population was spread out with 28.2% under the age of 18, 8.4% from 18 to 24, 28.0% from 25 to 44, 20.8% from 45 to 64, and 14.6% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 94.1 males. For every 100 females age 18 and over, there were 90.3 males.
The median income for a household in the city was $38,874, and the median income for a family was $48,669. Males had a median income of $30,980 versus $22,063 for females. The per capita income for the city was $18,345. About 4.5% of families and 6.9% of the population were below the poverty line, including 7.7% of those under age 18 and 6.5% of those age 65 or over.